1. Field of the Invention
The present invention relates to a server, a client, and a method for shutting down the power of computers on a network.
2. Description of the Related Art
A function called Wakeup On LAN (local area network) (hereinafter, referred to as WOL) enables predetermined computers on a network to be powered on in conjunction with the power-on operation of a different computer on the same network. With this WOL function, a server in a power-off state can be powered on according to a command from a client. Thus, the WOL function is widely used particularly in personal computers such as IBM PC/AT-compatible computers.
Furthermore, power on/off of some audio and visual (AV) devices can also be linked with the power on/off operation of another device. For example, a display device can be powered on in conjunction with the power-on operation of a video cassette recorder (VCR), as disclosed in Japanese Unexamined Patent Application Publication No. 2003-69585.
As described above, the WOL function is widely used in the world of personal computers. Unfortunately, a function for turning off the power of a computer in conjunction with the power off operation of another computer has not yet been realized. This is because a personal computer is required to process complicated conditions to determine whether or not the power can be safely turned off when the computer receives an external power-off request. As a result, if this determination is made improperly, unintended shutdown of the personal computer may occur.